Preheat the oven to 350°.
Spray a 9" X 5" X 3" loaf pan with no-stick spray and set aside.
In a large bowl, stir together the all-purpose flour, whole-wheat flour, sugar, baking powder, cinnamon, baking soda, salt, nutmeg and cloves.
Make a well in the center of the mixture.
In another large bowl, beat the egg whites until foamy.
Stir in the applesauce, buttermilk and vanilla.
Then stir in the zucchini until well combined.
Add the zucchini mixture to the flour mixture and stir just until moistened.
Fold in the walnuts.
Pour the batter into the prepared pan.
Bake for 40 to 50 minutes or until a toothpick inserted in the center comes out clean.
Cool the bread in the pan for 10 minutes.
Then remove the bread and cool completely on a wire rack before slicing.